"Ocean acidification refers to a reduction in the pH of the ocean over an extended period time, caused primarily by uptake of carbon dioxide (CO2) from the atmosphere."

 

-As carbon dioxide is released into the atmosphere from the burning of fossil fuels, scientists have found that 30 to 40% of this carbon ends up being abosrbed into water systems (oceans, rivers, lakes and streams). The absorbed carbon changes chemical compounds in the water, causing the pH level to reduce in number (causing the water to become more acidic). This rise in acidity leads to consequences such as depressing the metabolic rate and immune response in organisms as well as causing coral bleaching.

 

In regards to the change of water's chemical composition, dissolving CO2 in seawater increases the hydrogen ion (H+) concentration in the ocean, and thus decreases ocean pH. The following balanced equation clearly represents this process:

 

"CO2 (aq) + H2O H2CO3 HCO3− + H+ CO32− + 2 H+"

 

FACTS ABOUT OCEAN ACIDIFICATION:

-"Prior to industrialization, the concentration of carbon dioxide in the atmosphere was 280 parts per million (ppm). With increased      use of fossil fuels, that number is now approaching 400 ppm and the growth rate is accelerating." 

-Carbonic ions decrease as acidity rises making it hard for marine organisms to form shells for protection.

-Every 0.1 unit change of pH = 30% acidity increase in the ocean